Fetal movement monitor

Abstract

The invention concerns fetal movement monitoring apparatus having a deflection sensor device arranged to be applied to a mother's abdomen for detection of abdominal deflections indicative of fetal movements and to output a signal comprising one or more record of said abdominal deflections. A processor under the control of machine readable instructions is arranged to process the signal output from the deflection sensor device and to output a log of fetal movement over time. The processor is arranged to receive one or more further input indicative of maternal or fetal movement or wellbeing, for example from a second sensor device by which a user can input a record of perceived fetal movements. The processor may compare the output of the first sensor device and the user's input via the second sensor device and output a log of fetal movements over time based upon said comparison.

The invention claimed is: 
     
       1. A fetal movement monitoring apparatus comprising:
 a first sensor device comprising a piezoelectric or piezoresistive sensor component configured to be applied to a mother's abdomen for detection of fetal movements, wherein the first sensor device is configured to output a signal comprising one or more record of said fetal movements; 
 a second sensor device in a receiving device to detect user input comprising a record of perceived fetal movements; and 
 one or more processor under the control of machine readable instructions configured to:
 detect that the fetal movement monitoring apparatus comprises a mode of operation that is based at least in part on a combination of the signal from the first sensor device and the user input detected by the second sensor device, wherein the first sensor device and the second sensor device are both included as part of the fetal movement monitoring apparatus; 
 compare the signal of the first sensor device and the user input detected by the second sensor device; 
 determine a confidence value associated with said comparison; 
 calibrate the first sensor device based upon said comparison; and 
 process the signal from the first sensor device to output a log of the fetal movements during a period of time and the confidence value. 
 
 
     
     
       2. The fetal movement monitoring apparatus according to  claim 1 , wherein the first sensor device comprises a deflection sensor arranged to sense deflections in the mother's abdomen indicative of a fetal movement. 
     
     
       3. The fetal movement monitoring apparatus according to  claim 1  wherein the first sensor device comprises a plurality of fetal movement sensors arranged at spaced locations and/or different relative orientations. 
     
     
       4. The fetal movement monitoring apparatus according to  claim 1  wherein the first sensor device comprises a patch comprising an adhesive material for adhering the patch to the mother's abdomen. 
     
     
       5. The fetal movement monitoring apparatus according to  claim 1 , wherein the first sensor device comprises an intelligent textile material to be worn by the mother in the abdominal region, the stress/strain in said textile material being sensed to provide an indication of fetal movement. 
     
     
       6. The fetal movement monitoring apparatus according to  claim 1 , wherein the second sensor device comprises a tactile sensor and a timer or clock, which may be synchronised with a corresponding timer or clock in the first sensor device. 
     
     
       7. The fetal movement monitoring apparatus according to  claim 6 , wherein the second sensor device comprises a user interface device, separate from the first sensor device and arranged for data communication therewith, the user interface device having one or more processors for processing of the sensor signals. 
     
     
       8. The fetal movement monitoring apparatus according to  claim 7 , wherein the user interface device has a display and the one or more processors control output of prompts to the user to commence input of perceived maternal movements using the device. 
     
     
       9. The fetal movement monitoring apparatus according to  claim 1 , wherein the first sensor device comprises any, or any combination, of an amplifier, bandpass filter, analogue-to-digital converter and/or data sampler. 
     
     
       10. The fetal movement monitoring apparatus according to  claim 1 , comprising a further sensor in the form of a maternal movement sensor, the further sensor being different to the first or second sensor and being arranged to sense coarse maternal movement. 
     
     
       11. The fetal movement monitoring apparatus according to  claim 10 , wherein the maternal movement sensor is arranged to be applied to the mother's skin, or worn by the mother, as part of the first sensor device. 
     
     
       12. The fetal movement monitoring apparatus according to  claim 10 , wherein the maternal movement sensor comprises an accelerometer. 
     
     
       13. The fetal movement monitoring apparatus according to  claim 10 , wherein the one or more processor is arranged to compare a signal output from the maternal movement sensor with the signal output from the first sensor device and to output the log of fetal movements over time based upon said comparison. 
     
     
       14. The fetal movement monitoring apparatus according to  claim 13 , wherein the processor is arranged to process the signal output from the first sensor device and to accept or record or reject an instance of fetal movement in dependence upon a concurrent sensed level of maternal activity. 
     
     
       15. The fetal movement monitoring apparatus according to  claim 1 , wherein the comparison performed by the processor comprises comparing the time and/or magnitude of any records or signals. 
     
     
       16. The fetal movement monitoring apparatus according to  claim 1 , wherein the log of fetal movements comprises a summation or count of fetal movements over a predetermined time period. 
     
     
       17. The fetal movement monitoring apparatus according to  claim 1 , wherein the processor compares the log of fetal movements to one or more predetermined threshold value, such as a predetermined count or rate of fetal movement and/or a predetermined rate of change of fetal movement and outputs a signal indicative of abnormal fetal movement if the log of fetal movement meets or passes said one or more predetermined threshold value. 
     
     
       18. The fetal movement monitoring apparatus according to  claim 17 , wherein the threshold value is a variable which varies according to a predetermined trend and/or in response to previous logs of fetal movement. 
     
     
       19. The fetal movement monitoring apparatus according to  claim 1 , wherein the processor is configured to compare the output of the first sensor device and the user input detected by the second sensor device in response to an indication of abnormal fetal activity. 
     
     
       20. The fetal movement monitoring apparatus according to  claim 1 , further comprising a transmitter for transmitting the log of fetal activity or an alert signal derived therefrom to a remote location. 
     
     
       21. A method of monitoring fetal movement comprising:
 obtaining or receiving a signal comprising a first record of fetal movements from a first sensor device applied to a mother's abdomen; 
 obtaining or receiving a second record of perceived fetal movements manually input by a user for a time period concurrent with the first record of fetal movement; and 
 using one or more processor under the control of machine readable instructions to:
 compare the signal of the first sensor device and the user input; 
 determine a confidence value associated with said comparison; 
 calibrate the first sensor device based upon said comparison; and 
 process the signal from the first sensor device to output a log of the fetal movements during a period of time and the confidence value. 
 
 
     
     
       22. The method according to  claim 21 , wherein the user is the mother. 
     
     
       23. A data carrier comprising machine readable instructions for the control of one or more processors to:
 receive a signal comprising a first record of fetal movements from a first sensor device applied to a mother's abdomen; 
 receive a second record of perceived fetal movements manually input by a user for a time period concurrent with the first record of fetal movement; 
 compare the signal of the first sensor device and the user input; 
 determine a confidence value associated with said comparison; 
 calibrate the first sensor device based upon said comparison; and 
 process the signal from the first sensor device to output a log of the fetal movements during a period of time and the confidence value.